1. Technical Field
The present invention relates to a thin film transistor, a method of manufacturing the same, and an image display apparatus.
2. Background Art
According to the current state of information technology, information is frequently transmitted from and received with lap top computers or other types of portable information terminals. It is common knowledge that a ubiquitous society enabling information to be exchanged anywhere may be attained in the near future. In such a society, lighter and slimmer information terminals could be desirable. Currently, silicon-based material is mainly employed as a semiconductor material and photolithography is generally used as a manufacturing method.
On the other hand, printable electronics in which an electrical component is manufactured by using a printing technique is attracting attention. By using a printing technique, the following advantages may be attained, that is, equipment cost and manufacturing cost may be reduced compared to using the photolithography and, because a vacuum and a high temperature environment are not necessary, a plastic substrate could be used. Further, this printing technique might be applied to a wide range of fields, not only to thin and light flexible displays but such as also to RFID (Radio Frequency Identification) tags and sensors. Thus, research into printable electronics could be important.
To form a semiconductor layer from solution, methods such as but not limited to a spin coating method, a dipping method, and an ink jet method can be applied. Among these methods, in a transistor array in which a plurality of transistors are arranged, each being manufactured with the spin coating method or the dipping method, because current is likely to flow in the semiconductor layer between transistor elements or between transistors and pixel electrodes, current (leak current) in the Off state becomes larger, which causes a problem with the On-Off ratio being decreased.
Therefore, for example, in patent literature 1, a semiconductor layer is formed at a desired location by using the ink jet method, whereby electrical isolation between the transistor elements is accomplished. Moreover, for example, in patent literature 2, a semiconductor solution is injected into a channel portion located between a source electrode and a drain electrode, whereby electrical isolation between the transistor elements is accomplished.